Enhanced activation of neurons in prelunate cortex before visually guided saccades of trained rhesus monkeys.

Single unit recording from trained rhesus monkeys demonstrate that the activity of the prelunate cortex is enhanced when a visual stimulus becomes a target of saccadic eye movement. As a rule, the enhancement is spatially selective: it does not occur if the animal makes an eye movement away from, rather than towards the stimulus. The results show that the prelunate cortex has access to an extra-retinal signal which is activated in association with events preceding visually guided eye movements. Whether the signal reflects the initiation of eye movement of the animal's interest in the stimulus, which he usually selects to initiate an eye movement, remains uncertain.